The Role Of Acetylation And AMPK In Postmortem Muscle Glycolysis

PSE(Pale, Soft, Exudative) meat is characterized by a paler colour, a higher toughness and a lower water-holding capacity. Due to its poor quality and inferior color results in enormous economic loss to the meat industry. PSE meat was caused by an early accumulation of lactic acid, due to rapid postmortem glycolysis. However, the regulation of glycolysis in postmortem muscle is not well understood.Reversible posttranslational modification(PTM) plays a important role in regulating diverse cellular functions. Recently, acetylation on lysine resides of non-histone proteins has been shown to play a major role for controlling cell metabolic processes. In this study, we got several results as follows:1. Pre-slaughter stress promoted glycolysis by enhancing the acetylation level of postmortem muscle. preslaughter stress induced by swimming significantly accelerated glycolysis of postmortem muscle. Moreover, the acetylation level was higher in the postmortem muscle of mice stressed by swimming. These results suggest that the pre-slaughter stress can enhance the acetylation of proteins.2. Higher level of acetylation promoted glycolysis. Intraperitoneal injection of HDACs inhibitor promoted glycolysis; in contrast, intraperitoneal injection of HATs inhibitor inhibited glycolysis. In addition, intraperitoneal injection of HDACs and HATs inhibitor to increase and reduce the acetylation level of proteins respectively. These results suggest that higher level of acetylation can promote glycolysis of postmortem muscle.3. AMPK enhanced the acetylation level of postmortem muscle. Intraperitoneal injection of AICAR activated AMPK and accelerated glycolysis of postmortem muscle. Moreover, the acetylation level was higher in the postmortem muscle of mice injected with AICAR. These results suggest that AMPK can promote glycolysis by enhancing the acetylation level of postmortem muscle.